Revision 73863ab028579ed98c4f1f36d016536b1b415344 authored by Anton Vorontsov on 31 May 2012, 23:26:23 UTC, committed by Linus Torvalds on 01 June 2012, 00:49:29 UTC
Current CPU hotplug code has some task->mm handling issues: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so we must take the task lock while handle its mm. 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has all the issues fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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rate.h
/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef IEEE80211_RATE_H
#define IEEE80211_RATE_H
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "sta_info.h"
#include "driver-ops.h"
struct rate_control_ref {
struct ieee80211_local *local;
struct rate_control_ops *ops;
void *priv;
};
void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta,
struct ieee80211_tx_rate_control *txrc);
static inline void rate_control_tx_status(struct ieee80211_local *local,
struct ieee80211_supported_band *sband,
struct sta_info *sta,
struct sk_buff *skb)
{
struct rate_control_ref *ref = local->rate_ctrl;
struct ieee80211_sta *ista = &sta->sta;
void *priv_sta = sta->rate_ctrl_priv;
if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
return;
ref->ops->tx_status(ref->priv, sband, ista, priv_sta, skb);
}
static inline void rate_control_rate_init(struct sta_info *sta)
{
struct ieee80211_local *local = sta->sdata->local;
struct rate_control_ref *ref = sta->rate_ctrl;
struct ieee80211_sta *ista = &sta->sta;
void *priv_sta = sta->rate_ctrl_priv;
struct ieee80211_supported_band *sband;
if (!ref)
return;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
ref->ops->rate_init(ref->priv, sband, ista, priv_sta);
set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
}
static inline void rate_control_rate_update(struct ieee80211_local *local,
struct ieee80211_supported_band *sband,
struct sta_info *sta, u32 changed)
{
struct rate_control_ref *ref = local->rate_ctrl;
struct ieee80211_sta *ista = &sta->sta;
void *priv_sta = sta->rate_ctrl_priv;
if (ref && ref->ops->rate_update)
ref->ops->rate_update(ref->priv, sband, ista,
priv_sta, changed);
drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
}
static inline void *rate_control_alloc_sta(struct rate_control_ref *ref,
struct ieee80211_sta *sta,
gfp_t gfp)
{
return ref->ops->alloc_sta(ref->priv, sta, gfp);
}
static inline void rate_control_free_sta(struct sta_info *sta)
{
struct rate_control_ref *ref = sta->rate_ctrl;
struct ieee80211_sta *ista = &sta->sta;
void *priv_sta = sta->rate_ctrl_priv;
ref->ops->free_sta(ref->priv, ista, priv_sta);
}
static inline void rate_control_add_sta_debugfs(struct sta_info *sta)
{
#ifdef CONFIG_MAC80211_DEBUGFS
struct rate_control_ref *ref = sta->rate_ctrl;
if (ref && sta->debugfs.dir && ref->ops->add_sta_debugfs)
ref->ops->add_sta_debugfs(ref->priv, sta->rate_ctrl_priv,
sta->debugfs.dir);
#endif
}
static inline void rate_control_remove_sta_debugfs(struct sta_info *sta)
{
#ifdef CONFIG_MAC80211_DEBUGFS
struct rate_control_ref *ref = sta->rate_ctrl;
if (ref && ref->ops->remove_sta_debugfs)
ref->ops->remove_sta_debugfs(ref->priv, sta->rate_ctrl_priv);
#endif
}
/* Get a reference to the rate control algorithm. If `name' is NULL, get the
* first available algorithm. */
int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
const char *name);
void rate_control_deinitialize(struct ieee80211_local *local);
/* Rate control algorithms */
#ifdef CONFIG_MAC80211_RC_PID
extern int rc80211_pid_init(void);
extern void rc80211_pid_exit(void);
#else
static inline int rc80211_pid_init(void)
{
return 0;
}
static inline void rc80211_pid_exit(void)
{
}
#endif
#ifdef CONFIG_MAC80211_RC_MINSTREL
extern int rc80211_minstrel_init(void);
extern void rc80211_minstrel_exit(void);
#else
static inline int rc80211_minstrel_init(void)
{
return 0;
}
static inline void rc80211_minstrel_exit(void)
{
}
#endif
#ifdef CONFIG_MAC80211_RC_MINSTREL_HT
extern int rc80211_minstrel_ht_init(void);
extern void rc80211_minstrel_ht_exit(void);
#else
static inline int rc80211_minstrel_ht_init(void)
{
return 0;
}
static inline void rc80211_minstrel_ht_exit(void)
{
}
#endif
#endif /* IEEE80211_RATE_H */
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